DTAB降低饱和烷烃与水的界面张力的研究

判断一种表面活性剂降低油-水界面张力性能的优劣,就需要对界面张力进行准确有效的测量。文章就不同浓度的十二烷基三甲基溴化铵(DTAB)水溶液分别与正庚烷(n-Heptane)和正十六烷(n-Hexadecane)之间的界面张力进行定量的测量,分别得到了在30℃下水-正庚烷和水-正十六烷体系的界面张力随DTAB浓度变化的曲线。结果表明,在DTAB浓度达到其所在体系中的CMC值时,水-正庚烷体系界面张力小于水-十六烷体系界面张力。DTAB具有较强的抗矿盐能力,界面张力随温度升高有所下降。     

不同体系中油酸甲酯与烷基苯磺酸盐协同效应研究

研究了表面活性剂/盐/模拟油体系与表面活性剂/碱/模拟油体系中油酸甲酯与表面活性剂协同效应机理.结果表明两种体系中协同效应机理不同.在盐体系中,油酸甲酯主要通过改变油相的等效烷烃碳数(EACN) 影响表面活性剂在油水相分配.而碱体系中,油酸甲酯影响表面活性剂在油水相分配从而影响界面张力；另一方面,油酸甲酯吸附在界面上顶替表面活性剂分子影响界面张力.对于不同结构表面活性剂,两种作用竞争的结果不同.     

系列烷基苯磺酸盐对烷烃的动态界面张力研究

从表面活性剂分子量、表面活性剂浓度、电解质浓度、烷烃碳数等方面考察了系列烷基苯磺酸盐异构体纯化合物的油水动态界面张力行为.研究表明,表面活性剂分子量增大和电解质浓度增加使界面张力动态变化减慢,达到平衡所需时间延长;表面活性剂浓度增加和烷烃碳数增加使界面张力动态变化加快,达到平衡所需时间减少.     

系列烷基苯磺酸盐对烷烃的动态界面性能研究

从表面活性剂分子量、表面活性剂浓度、电解质浓度、 烷烃碳数等方面考察了系列烷基苯磺酸盐异构体纯化合物的油水动态界面张力行为。研究表明,表面活性剂分子量越大和电解质浓度增加使界面张力动态变化越慢,达到平衡所需时间越长;表面活性剂浓度增加和烷烃碳数增加使界面张力动态变化加快,达到平衡所需时间减少。     

Triton X-100/甲苯/水三元体系界面张力的耗散颗粒动力学模拟

采用耗散颗粒动力学方法在介观层次上模拟了非离子表面活性剂Triton X-100 在油/水界面上的分布行为, 并把用于油/水二元体系界面张力的计算方法拓展到含表面活性剂的三元体系. 利用该方法可以得到与实验数值吻合的界面张力数据. 另外, 模拟结果直观展示了表面活性剂界面张力与界面密度的关系, 为表面活性剂复配增效理论提供了依据. 该模拟方法给出的微观信息可以为驱油体系配方筛选和表面活性剂有效应用提供指导.     

表面活性剂与油相动态界面张力影响因素研究

对不同类型表面活性剂烷基糖苷(APG1214)、咪唑啉(IAS)、十二烷基苯磺酸钠(SDBS)、烷基酚醚羧酸盐(ss-231)的油水动态界面张力进行了研究。在60℃,5 000 r·min-1条件下,考察了表面活性剂的浓度、表面活性剂的结构、正构烷烃碳数以及原油中活性物质对形成低界面张力影响。实验结果表明:表面活性剂亲水基的亲水性越强,亲水基之间排斥力越小,使得在油水界面排布的密度越大,降低界面张力的效果会更好;当表面活性剂疏水碳链与烷烃碳链相似时,降低界面张力的效果会更明显;无碱体系中原油中的活性物质可在油水界面上形成粘弹性界面膜,这种界面膜的形成减少了表面活性剂分子在界面的吸附,使界面张力升高。     

支化十六烷基甲苯磺酸钠的油水界面张力

研究了自制的3种十六烷基甲苯磺酸钠,在正构烷烃/水体系的界面性能. 分别考察了磺酸盐脂肪链支化程度及浓度等以及外加助剂脂肪醇类型和无机盐浓度对磺酸盐最小烷烃碳数nmin和界面张力值的影响. 结果表明,磺酸盐支化程度增加,其nmin变大,最低界面张力值变小;随着磺酸盐浓度的增加,界面张力值先下降后上升;随着助剂脂肪醇碳链长度的增加,其nmin逐渐变大;无机盐的影响则表现为随着盐浓度的增加界面张力值先下降后上升,超低界面张力值出现在一个适宜的盐浓度范围内.     

十六烷基甲苯磺酸钠的界面性能研究

用自制的3种十六烷基甲苯磺酸钠,研究了其正构烷烃/水体系的界面性能。分别考察了磺酸盐支化程度及浓度等内部因素以及外加助剂脂肪醇类型和无机盐浓度等外界因素对磺酸盐最小烷烃碳数n_min以及界面张力值的影响。结果表明,磺酸盐支化程度增加,其n_min变大,最低界面张力值变小;而随着磺酸盐浓度的增加,界面张力值先下降后上升;随着助剂脂肪醇碳链长度的增加,其n_min逐渐变大;无机盐的影响则表现为随着盐浓度的增加界面张力值先下降后上升,超低界面张力值出现在一个适宜的盐浓度范围内。     

高盐油藏下两性/阴离子表面活性剂协同获得油水超低界面张力

研究了在高盐油藏中, 利用两性/阴离子表面活性剂的协同效应获得油水超低界面张力的方法. 两性表面活性剂十六烷基磺基甜菜碱与高盐矿化水具有很好的相容性, 但在表面活性剂浓度为0.07%-0.39%(质量分数)范围内仅能使油水界面张力达到10^-2 mN·m^-1量级, 加入阴离子表面活性剂十二烷基硫酸钠后则可与原油达到超低界面张力. 通过探讨表面活性剂总浓度、金属离子浓度、复配比例对油水动态界面张力的影响, 发现两性/阴离子表面活性剂混合体系可以在高矿化度、低浓度和0.04%-0.37%的宽浓度范围下获得10^-5 mN·m^-1量级的超低界面张力, 并分析了两性/阴离子表面活性剂间协同获得超低界面张力的机制.     

CMC系列高分子表面活性剂与原油超低界面张力形成机理的研究

采用动态激光光散射及环境扫描电镜研究了羧甲基纤维素系列高分子表面活性剂与大庆原油形成超低界面张力的机理.结果表明,CMC系列高分子表面活性剂具有与低分子量表面活性剂相比拟的表/界面活性,其水溶液的表面张力可达2835mN/m,界面张力达到10^-110mN/m.碱的加入可显著降低高分子表面活性剂与原油的界面张力,在适当条件下界面张力达到超低值(10^-3mN/m),可望作为三次采油的驱油剂.等效烷烃模型研究表明,用碱与原油酸性组分的作用来解释碱能使界面张力下降至超低值的传统观点是不完善的,加入碱能使高分子表面活性剂胶束解缔,胶束数量增多,胶束粒径减小,单分子自由链增加,有利于高分子表面活性剂向界面迁移和排布,这是高分子表面活性剂和碱复配体系与原油界面张力下降至超低值的主要原因.     

不同电性Gemini表面活性剂界面扩张性质

利用Langmuir槽法研究了含聚氧乙烯醚链中间链的两性Gemini表面活性剂C8E4NC12、阳离子Gemini表面活性剂C12NE3NC12和阴离子Gemini表面活性剂C8E4C8在空气/水表面和癸烷/水界面上的扩张性质,考察浓度对3种Gemini表面活性剂溶液表、界面扩张性质的影响.结果表明,由于分子间存在库仑引力,两性Gemini分子表现出较高的扩张弹性和粘性,且界面扩张性质类似于表面.对于有相同电荷Gemini分子,C8E4C8分子中的刚性苯环导致其疏水长链在表面上的取向不同于C12NE3NC12分子,两者表现出不同的表面扩张性质;而油分子能改变同电荷Gemini分子中长链烷基的取向,造成其界面扩张弹性和粘性远低于表面.提出了不同电性Gemini分子在界面排布的示意图,并利用弛豫过程的特征参数进行了验证.     

Emulsification properties of a star-shaped anionic surfactant in oil-based drilling fluid

A novel star-shaped sulfonate surfactant, synthesized with triethanolamine, was identified as a hydrophilic emulsifier which could form a stable water-in-oil emulsion. The interfacial film strength was measured by suspension drop method. The emulsification properties of emulsions were obtained by the emulsification rate experiment and demulsification voltage measurement. The emulsion shows an excellent emulsification effect when the addition of star-shaped anionic surfactant into oil-based drilling fluid was 2.0?wt%. In addition, the properties of surfactant in drilling fluid with different adding amounts were studied by rheological properties, thermal stability analysis and filtration experiments. The results show that star-shaped anionic surfactant used as emulsifier can improve the performance in oil-based drilling fluid, which maybe provides a new idea for this type of surfactant.     

Dilational properties of gemini surfactant/polymer systems at the air–water surface

The surface properties of mixed system containing gemini anionic surfactant 1,2,3,4-butanetetracarboxylic sodium, 2,3-didodecyl ester and partly hydrolyzed polyacrylamide were investigated by surface tension measurements and oscillating bubble methods. The influences of surfactant concentration, dilational frequency, temperature, pH, as well as salts on dilational modulus were explored. Meanwhile, the interfacial tension relaxation method was employed to obtain the characteristic time of surface relaxation process. The polymers play important roles in changing the interfacial properties especially at lower surfactant concentration. The possible mechanism of the polymer in changing the interfacial properties is proposed. Both the hydrophobic and electrostatic interaction among the surfactants and polymers dominate the surface properties of mixed system. These dynamic properties are of fundamental interest in understanding the structure of adsorption layers, dynamics of surfactant molecules, and their interaction with polymers at the surface.     

Interfacial molecular array behaviors of mixed surfactant systems based on sodium laurylglutamate and the effect on the foam properties

The foam properties of mixtures of an eco-friendly amino-acid derived surfactant sodium lauroylglutamate (LGS) interacting with cationic surfactant dodecyl trimethyl ammonium bromide (DTAB), nonionic surfactant laurel alkanolamide (LAA) and anionic surfactant sodium dodecyl sulfonate (SDS), were investigated, respectively. It was amazing that the three investigated binary-mixed systems all showed obviously synergism effect on foaming, though LGS/DTAB catanionic mixture showed remarkable synergistic effect with no surprise. The equilibrium and dynamic surface activity, along with the interfacial molecular array behaviors of binary-mixed systems with different molar ratios at air/water surface were also studied. Moreover, the theoretical simulation was employed to investigate how the interfacial behaviors of surfactants at air/water surface affected the foam properties. The study might provide the meaningful guidance for utilizing the LGS-based systems, especially in constructing eco-friendly foam systems in the application areas of cosmetics, medicine and detergent.     

阴阳离子表面活性剂混合体系在克拉玛依油田中获得超低界面张力

利用阴阳离子表面活性剂复配技术,在克拉玛依油田实际油水体系中获得了超低界面张力.通过添加非离子保护剂的第三组分,阴阳离子表面活性剂混合体系在克拉玛依油田回注水体系中的溶解度大大提高.确定了相关体系能够获得超低界面张力的表面活性剂的浓度和混合的比例范围,在克拉玛依油田的多个实际油水体系中获得了具有较大复配比例和较低表面活性剂浓度的实际配方,其中部分体系油水界面张力可接近10-4mN·m-1.同时,这类阴阳离子表面活性剂混合体系具有很好的抗吸附能力,在石英砂吸附72 h后体系依然呈现优良的超低界面张力.     

The Fast Relaxation Process between Hydrophobically Modified Associating Polyacrylamide and Different Surfactants at the Water‐Octane Interface

In our previous work (Macromolecules 2004, 37:2930), we found that the hydrophobic blocks of polyacrylamide modified with 2‐phenoxylethyl acrylate (POEA) and anionic surfactant sodium dodecyl sulfate (SDS) may form mixed associations at octane/water interface. However, the process involving the exchange of surfactant molecules between monomers and mixed associations in interface is so fast that we cannot obtain its characteristic time. In this article, the interfacial dilational viscoelastic properties of another hydrophobically associating block copolymer composed of acrylamide (AM) and a low amount of 2‐ethylhexyl acrylate (EHA) (<1.0 mol%) at the octane‐water interfaces were investigated by means of oscillating barriers method and interfacial tension relaxation method respectively. The influences of anionic surfactant SDS and nonionic surfactant Triton X‐100 on the dilational viscoelastic properties of 7000 ppm polymer solutions were studied. The results showed that the interaction between P(AM/2‐EHA) and SDS was similar to that of P(AM/POEA) and SDS. Moreover, we got the relaxation characteristic time of the fast process involving the exchange of s Triton X‐100 molecules between monomers and mixed associations.

We also found that the interfacial tension response of hydrophobically associating water‐soluble copolymers to the sinusoidal oscillation of interfacial area at low bulk concentration is as same as that of the typical surfactants: the interfacial tension decreases with the decrease of interfacial area because of the increase of interfacial active components. However, the interfacial tension increases with the decrease of interfacial area at 7000 ppm P(AM/2‐EHA), which is believed to be correlative with the structure of absorbed film. The results of another hydrophobically associating polymer P(AM/POEA) and polyelectrolyte polystyrene sulfonate (PSS) enhanced our supposition. The phase difference between area oscillation and tension oscillation has also been discussed considering the apparent negative value.     

双链阴离子表面活性剂1-烷基-癸基磺酸钠在气/液界面聚集行为:分子动力学模拟研究

采用分子动力学模拟方法研究了双链阴离子表面活性剂1-烷基-癸基磺酸钠(1-C_m-C_9-SO_3Na)在气/液界面的聚集行为。通过分析体系中各组分的密度分布和径向分布函数,考察了m大小对其界面性质的影响。结果表明:随着m的增大,表面活性剂的疏水性增强,疏水碳链的倾斜角也随之降低;m=4时,1-C_4-C_9-SO_3Na分子采用平躺的方式在界面上聚集,S-Na~+和S-S的相互作用最大,极性头基的水化能力最弱。通过模拟和实验对比得出,m增加到4个时,对该类双链阴离子表面活性剂性能的提高最显著。     

疏水缔合共聚物与表面活性剂的界面相互作用

采用界面张力弛豫法研究了疏水缔合聚合物聚丙烯酰胺/2-乙基己基丙烯酸酯[P(AM/2-EHA)]在正辛烷-水界面上的扩张粘弹性质, 考察了不同类型表面活性剂十二烷基硫酸钠(SDS)、聚环氧乙烯醚(Tx-100)和十六烷基三甲基溴化铵(CTAB)对其界面扩张性质的影响. 研究发现, 界面上的表面活性剂分子可以与聚合物的疏水嵌段形成类似混合胶束的聚集体, 表面活性剂分子与聚集体之间存在快速交换. 这种弛豫过程的特征时间远比分子在体相与界面间的扩散交换时短. 当界面面积增大时, 上述混合胶束中的表面活性剂分子能快速释放, 在界面层内原位快速消除界面张力梯度, 从而大大降低界面扩张弹性. 界面上的CTAB分子与聚合物链节上的负电中心通过较强的电荷吸引作用形成复合物. 当界面面积增大时, 上述混合胶束中的CTAB分子释放较慢, 界面张力梯度较大. 非离子表面活性剂Tx-100分子量较大, 扩散速率较慢, 它在界面上与聚集体间的交换比阴离子表面活性剂SDS慢, 其特征时间约为0.9 s.     

The effect of surfactants on the pH transition interval of bromothymol blue immobilized on XAD 4

Cationic, anionic and non-ionic surfactants adsorb readily from aqueous solution on to Amberlite XAD 4. The ionic surfactants cause the pH of the solution in contact with the resin to differ from that in the bulk of solution, cationic surfactants increasing the interfacial pH and anionic surfactants decreasing it. This causes a shift in the pH transition interval of a co-adsorbed pH indicator when measured with respect to the bulk solution. The quantity of ionic surfactant adsorbed tends to a constant value (presumably monolayer coverage) with increasing solution concentration, this amount being a function of the individual surfactant, whereas non-ionic surfactants readily form multilayers. Significant adsorption occurs when the surfactant possesses at least 14 carbon atoms.